“No; not for amateurs. But if we had been professionals, I believe we should have gone at it from the other end. The Robert end. We’ve been wondering about Mark and Cayley all the time. Now let’s wonder about Robert for a bit.”

“We know so little about him.”

“Well, let’s see what we do know. First of all, then, we know vaguely that he was a bad lot⁠—the sort of brother who is hushed up in front of other people.”

“Yes.”

“We know that he announced his approaching arrival to Mark in a rather unpleasant letter, which I have in my pocket.”

“Yes.”

“And then we know rather a curious thing. We know that Mark told you all that this black sheep was coming. Now, why did he tell you?”